Here's a fuller version using text file instead of database. This version also gets its data via xml from the European Central Bank - probably a more robust approach than scraping html from Yahoo.
Code lacks any kind of error trapping - recommend you add some.
Save the code below as [path]/converter.php
Enjoy.
Kevin
www.kenthouse.com
Code:
<?php
/*
File: Currency exchange rate updater
Author: Kevin Holdridge, wwww.kenthouse.com
Last modified: 11 May 2006
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
included GNU General Public License for more details. If you
received this file without the gpl.txt file, you may view it at:
http://www.gnu.org/copyleft/gpl.html
*/
/*
-----------------------------
Requirements & instructions:
-----------------------------
- Need PHP4.1+
- Must be able to set cron jobs
- Must be able to set 777 permissions on a text file to allow server to update the file holding the rates
- If you don't have PHP available on commandline, you'll need to alter the cron job to use CURL or another way of simulating http
- create empty text file to hold the rates data, and set permissions, e.g.:
touch /tmp/rateslist.php
chmod 0777 /tmp/rateslist.php
- Configure and save this file as [path]/converter.php
- Sample cron entry to update the rates daily:
06 00 * * * /usr/local/bin/php [path]/converter.php
- The first time this script runs, it will populate the local file with a list of currencies and rates
- Include the following code near the top of any file that displays price data in order to get the rate or rates into an array ($conversion_rates)
<?php
$conversion_rates = array();
$handle = @fopen($ratesfile, "r");
if ($handle)
{
while (!feof($handle))
{
$buffer = fgets($handle, 4096);
$pieces = explode(":", $buffer);
$key = $pieces[0];
$conversion_rates[$key]['label'] = $pieces[1];
$conversion_rates[$key]['rate'] = $pieces[2];
}
fclose($handle);
}
function docurconversion($val)
{
global $conversion_rates;
foreach($conversion_rates AS $k=>$v)
{
if($k)
{
$newfigure = number_format($val * $v['rate'], 2, '.', ',');
echo "{$v['label']}{$newfigure} ";
}
}
}
?>
- You can then convert or add occurrences of a price in your base currency to one or more alternative currencies
- e.g.
instead of
<?php
$a_figure = 5.50;
echo "£($a_figure}";
?>
use
<?php
$a_figure = 5.50;
docurconversion($a_figure);
?>
*/
/*
--------------------
CONFIGURATION BLOCK
--------------------
*/
//Location of remote xml file ... uisng European Central Bank in this case
$sourceurl="http://www.ecb.int/stats/eurofxref/eurofxref-daily.xml";
//Array of alternative currencies to cover (include currency code and html entity for currency label)
//... open the above xml file to get a list of supported currencies and their codes
$currencies = array(
'GBP' => '£',
'USD' => 'US$',
'AUD' => 'AUS$',
'CAD' => 'Canadian$',
'EUR' => '€'
);
//Your base currency ... use proper currency code (see above, must exist in remote xml file)
$base_currency = 'GBP';
//Adjustment factor ... you pay more than the bank's advertised rate to convert money, so use this factor to load the conversion
//e.g. '1' means no adjustment, '1.02' adds 2% to the calculation, '1.1' adds 10%
$adjuster = 1.02;
//path and filename of local file holding the rates
$ratesfile = '/tmp/rateslist.php';
/*
--------------------------------
NO CONFIGURATION NECESSARY BELOW
--------------------------------
*/
//Load source file
$sourcedata = @file_get_contents($sourceurl);
//parse remote xml file, if currency is on our list write currency code,label, and raw exchange rate (based on Euro) into array
$rates_array = array();
$p = xml_parser_create();
xml_parse_into_struct($p, $sourcedata, $vals, $index);
xml_parser_free($p);
$rates_array['EUR'] = array(
'label' => '€',
'rate' => 1
);
foreach ($vals as $k => $v)
{
if (array_key_exists('attributes', $v))
{
if(array_key_exists($v['attributes']['CURRENCY'], $currencies))
{
$curcode = $v['attributes']['CURRENCY'];
$curlabel = $currencies[$curcode];
$currate = $v['attributes']['RATE'];
$rates_array[$curcode] = array(
'label' => $curlabel,
'rate' => $currate
);
}
}
}
// get a factor to rework all the rates based on our base currency, not on Euro
$factor = $rates_array[$base_currency]['rate'];
// modify the rates based on the base currency
foreach(array_keys($rates_array) as $k)
{
$rates_array[$k]['rate'] = ($rates_array[$k]['rate'] / $factor) * $adjuster;
}
//write currency code, label and exchange rate into local file
$fp=fopen($ratesfile,"w");
foreach ($rates_array as $k => $v)
{
fputs($fp, "{$k}:{$v['label']}:{$v['rate']}\n");
}
fclose($fp);
?>
Originally Posted by Chap5
The basic script supplied works fine if evrything happens as expected. But what if the xml script can't be reached at update time? Or if one of the currencies you have selected can't be found in the xml? You could find that the system is serving out-of-date exchange rates because updating has failed, or worse, some or all of the currencies aren't set at all or are set at a zero rate causing wrong information to appear on your site.
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